Dehydration, less than ideal nutritional choices, fatigue from strenuous workouts, overtraining or just plain not getting enough rest can leave you feeling like your legs are made of lead weights while you're running. You don't have to let heavy legs interfere with your progress. No matter what your running purpose or goals, ensuring your body has what it needs to do what you're asking of it takes some consideration and planning before, during and after your workout.

Step 1

Warm up with an easy run before jumping right in at your target pace. When you start out, you should be going slow enough to carry on a conversation or sing, and gradually speed up to your target pace, rather than ramping up over the course of a few seconds. The warm up will help to stretch and prepare your muscles as well as your mind; it's a way of convincing your body that you are, in fact, going to run today.

Step 2

Progress slowly if you are trying to build up your mileage. The number one reason new runners give up before they have really given running a chance is because they try to do too much, too fast. You shouldn't increase your mileage by more than 10 percent each week.

Step 3

Incorporate rest days at least twice per week, and never do hard workouts on consecutive days. Overtraining and muscle fatigue can make your legs feel heavy, but even worse can cause tissue damage and pain.

Step 4

Hydrate properly before and during your exercise. Dehydration can cause cramps and lead to muscle fatigue and loss of coordination, which can lead to improper form and injury.

Step 5

Fuel your body for exercise. You need the proper amount of salts, carbohydrates and protein to prevent cramps and muscle fatigue -- leg heaviness -- during workouts and to encourage proper muscle repair after workouts. Registered dietician Karen Ansel identifies five nutrients essential to performance: vitamin E, iron, potassium, zinc and magnesium. You can get these nutrients from nuts, seeds, meats, a variety of beans and spinach.

Tips

Keep a log of your eating and sleeping patterns and relate them to how you feel during your workout.

About the Author

Ari Reid has a bachelor's degree in biology (behavior) and a master's in wildlife ecology. When Reid is not training to run marathons, she is operating a non-profit animal rescue organization. Reid has been writing web content for science, health and fitness blogs since 2008.